This invention relates in general to power transfer systems and more particularly the increase of power in such systems by automatically varying cylinder displacement and increasing average piston velocity.
Although the invention has applications to various machines which employ pistons reciprocable in cylinders, such as air compressors, pumps, refrigeration, air conditioning compressors and steam engines, its primary benefits relate to internal combustion engines where the greatest opportunities for conservation of energy are to be found.
The efficiency of internal combustion engines is notoriously low. Moreover, it is not usually possible to match the output of the engine to the demands placed upon it. Obviously, the power required for cruising at speeds of the order of 55 mph is relatively low as compared to the requirements for rapid acceleration. An engine designed for high-acceleration performance has low efficiency not only at cruising speeds but also at lower speeds, because the volume of the cylinder remains constant as do fueling requirements. This fact remains true whether the engine is of the Otto, diesel, or intermediate cycle.
Some attempts have been made to match internal combustion engines to the instantaneous requirements. Relatively recently, there has been developed an automotive engine which automatically selects only as many cylinders, say from 4 to 8, in accordance with the need. A similar approach has been taken on compressors in the past, and some success has been achieved, but drawbacks even in commercial engines of this type remain. By reducing the number of cylinders in use, some reduction of total volumetric displacement was of course accomplished. Nevertheless, the weight of the large engine remains even though less power is delivered when less power is needed.
Another approach to the reduction of volumetric displacement in internal combustion engines is shown in the relatively old U.S. Pat. No. 1,747,091, which issued to N. Trbojevich in 1930. In the patented design, an extensible connecting rod was used between each piston and the crankshaft of the engine. It was claimed that such extensible connecting rods permitted the use of higher combustion ratios and minimized predetonation because of the resilience of the connecting rods. The patented design has never been widely adopted apparently for several reasons. The extensible connecting rod mounted as it was conventionally within the engine was exposed to extremes of temperature and pressure as well as the often corrosive internal environment of the engine, with the result that the life of the mechanism was very short. Also, the fact that the piston is driven toward the crankshaft leads to various mechanical problems, room in the connecting rod area being very limited, close tolerances and linear alignment being necessary and high inertial forces tending to cause the extensible rod to distort and bind, leading to early fatigue.
It is an object of the present invention to vary the displacement of an engine in such a way as to transfer power efficiently.
It is a further object of the present invention to increase the efficiency of an internal combustion engine in terms of fuel consumption.
It is another object to increase engine output power by increasing average piston velocity.
It is a further object of the present invention to prevent excessive shock and stress loads on bearings and associated elements of internal combustion engines.